Changes in visual attention towards food cues after obesity surgery: An eye-tracking study

Conscious and pre-conscious attentional bias to food images in patients subjected to Roux-en-Y gastric bypass

Attentional bias (AB) to food after bariatric surgery might be a cognitive marker for weight regain. The visual probe task (VPT) is commonly used to capture AB at automatic, pre-conscious, and conscious orientation of attention. The aim of this study was to investigate how the preoperative BMI of patients submitted to Roux-en-Y gastric bypass (RYGB) impacts AB to food. We assessed patients who had preoperative BMI>50 (n = 28) or preoperative BMI<50 (n = 31) months after the RYGB procedure. Participants underwent clinical, psychological, and VPT evaluations. In VPT, pairs of food and matching non-food images were shown for 100 ms, 500 ms or 2000 ms and AB for food was assessed for each exposure time. A significant AB to food was observed at 2000 ms for all patients in this study, suggesting that the overall sample were consciously orienting their attention toward food cues after surgery, a finding that might be relevant for understanding weight control. When groups with preoperative BMI higher and lower than 50 kg/m2 were compared, a significant difference on AB to food stimuli at 500 ms was observed, controlling for excess weight lost since surgery and postoperative time. Subjects with preoperative BMI>50 had a positive and reliable AB to food while subjects with preoperative BMI<50 had a negative AB. This suggests that food stimuli have a higher incentive salience even after surgery for those with BMI>50, which might explain why subjects with higher preoperative weight have higher risks for weight regain. These results may indicate that RYGB can impact incentive salience for food cues in a differential manner, increasing conscious AB in all patients and decreasing pre-conscious AB only in those with BMI<50 kg/m2.

Eating disorder-specific rumination moderates the association between attentional bias to high-calorie foods and eating disorder symptoms: Evidence from a reliable free-viewing eye-tracking task

Cognitive theories of eating disorders implicate Attentional Bias (AB) towards food-related information in the development and maintenance of eating disorders. Empirical evidence for this proposal, however, has been inconsistent, and the measures used to examine AB to food-related stimuli typically showed poor reliability. The aim of the current study was twofold. Firstly, we aimed to examine the psychometric properties of a newly devised eye-tracking task for the assessment of AB in the context of eating disorders. Secondly, we examined the role of Eating Disorder-specific (ED-specific) rumination as a potential moderator of the association between attentional bias to food images and eating disorder symptoms. One hundred and three female students were recruited and completed an eye-tracking task comprising 21 matrices that each contained 8 low-calorie and 8 high-calorie food images. Each matrix was presented for 6 s. First fixation location, first fixation latency, and total dwell time were assessed for low and high-calorie food images and the dwell-time based AB measure showed good reliability based on Cronbach's alpha, McDonald's Omega, and split-half method. In addition, the results revealed that the ED-specific rumination plays the hypothesized moderating role. Specifically, while participants with high levels of ED-specific rumination exhibited a positive association between AB to high-calorie foods and eating disorder symptoms, this association was not present among participants with lower levels of ED-specific rumination. The employed free-viewing task seems a reliable measure of AB to food-related stimuli, and the moderation analysis emphasizes the critical role of ED-specific rumination for eating disorder symptoms. Implications, limitations, and directions for future research are discussed.